I wouldn't have fed them just before leaving... I can't trust any sitter to clean appropriately (plus they might lose the snake!) so I cut feeding two weeks before a trip so no animal will dirty a cage when I'm gone. Aside from water there shouldn't really be anything a sitter needs to do. With so many people in the house I would want as little contact with the snakes as possible so there's less of a chance for problems to occur. How long are you gone for?